Iron is an essential metal for living organisms but its level must be strictly controlled in cells, because ferrous ion induces toxicity by generating highly active reactive oxygen, hydroxyl radicals, through the Fenton reaction. In addition, ferric ion shows low solubility under physiological conditions. To overcome these obstacles living organisms possess Ferritin superfamily proteins that are distributed in all three domains of life: bacteria, archaea, and eukaryotes. These proteins minimize hydroxyl radical formation by ferroxidase activity that converts Fe2+ into Fe3+ and sequesters iron by storing it as a mineral inside a protein cage. In this study, we discovered that mycobacterial DNA-binding protein 1 (MDP1), a histone-like protein, has similar activity to ferritin superfamily proteins. MDP1 prevented the Fenton reaction and protects DNA by the ferroxidase activity. The
Publisher: Public Library of Science
Date Published: 16-June-2011
Author(s): Takatsuka M., Osada-Oka M., Satoh E., Kitadokoro K., Nishiuchi Y., Niki M., Inoue M., Iwai K., Arakawa T., Shimoji Y., Ogura H., Kobayashi K., Rambukkana A., Matsumoto S.